Appeal from the Circuit Court of Jefferson County. No. 00-CF-404 Honorable Terry H. Gamber, Judge, presiding.
 The opinion of the court was delivered by: Justice Donovan
 Defendant, Michael A. Walls, appeals his conviction of aggravated criminal sexual assault. Defendant raises the following three contentions on appeal to this court: (1) he was denied a fair trial when the court prevented him from presenting evidence attacking the complaining witness's credibility with a prior false accusation of a crime, (2) the trial was a nullity based on the use of a special assistant State's Attorney, and (3) section 12-14(d)(2) of the Criminal Code of 1961 (Criminal Code) (720 ILCS 5/12-14(d)(2) (West 2000)), which mandates a term of natural-life imprisonment for a second conviction of aggravated criminal sexual assault, is unconstitutional under section 11 of article 1 of the Illinois Constitution because it creates a disproportionate penalty when compared to other more serious crimes. For the following reasons, we affirm.
 On November 25, 2000, Kathy, her cousin Jackie, and defendant met at the Corner Tavern in Mt. Vernon, Illinois. Defendant and Kathy had met on an Internet chat room about six months before the incident involved in this case. Later that evening, the threesome left the Corner Tavern in defendant's van and, in search of money, visited the homes of several friends. When they failed to secure any cash, the trio went to Club 57. They left Club 57, and defendant and Kathy dropped Jackie off at the Corner Tavern and proceeded to defendant's trailer to search for money.
 Kathy's Testimony and Corroborative Evidence
 After entering the trailer, Kathy looked through a jar for money. Defendant gave her a beer. Kathy dropped her cigarettes, and when she bent over to pick them up, defendant hit her in the head with a hammer. Defendant then told Kathy to stay down or he would hurt her again. Defendant picked Kathy up and took her into the back bedroom and placed her on the bed. Defendant forced her to get on her hands and knees, tied her hands and feet, tied her to the bed, and put a cloth around her mouth.
 Defendant left the bedroom to go to the bathroom. When he returned, he pulled Kathy's pants and underwear down to her knees and placed his penis in her vagina. After he finished, defendant sat on the bed, untied Kathy, and told her that he was sorry. Defendant also told her that he would not blame her if she went to the police. Defendant then drove Kathy home and again told her he was sorry.
 Once inside her home, Kathy woke up her mother and told her that she had been raped. Her mother drove her to Good Samaritan Hospital in Mt. Vernon shortly after 1 a.m. At the hospital, Kathy spoke to several medical staff members and police officers about the incident. Kathy had a large knot on her head, described by hospital staff members as a hematoma. Dr. Richard Garretson, the emergency room physician at Good Samaritan Hospital, testified that the hematoma came from a blow to the head that had been very recent and that he believed that the hematoma was "consistent with the blow from the hammer." Kathy developed bruises on her ankles from being tied up. Medical personnel and police officers described the bruises as ligature marks.
 Defendant's Testimony
 When defendant and Kathy entered defendant's trailer, Kathy sat on the couch and asked defendant for a cigarette. Defendant gave Kathy his last beer. Defendant testified that Kathy seemed frustrated and angry because they could not come up with any money. Defendant stated that he then asked, "What would you say if I just up and just kissed you right here?" Kathy replied, "I got no problem with that." They then started kissing and things got "heated." Defendant and Kathy then stretched out on the couch. Kathy accidentally "bumped her head" on the edge of the couch, and she immediately grabbed her head and claimed she was in pain. Kathy was irritated but finally calmed down. Defendant then suggested they go to the bedroom.
 In the bedroom, they removed their clothes and defendant put on a condom before engaging in sexual intercourse. After a few minutes, defendant discovered that the condom had broken. He sat on the bed with his head in his hands. Defendant testified, "[Kathy] commenced to getting in my stuff, getting argumentative with me, [and] telling me not only was I broke but I was sexually unsatisfied and apparently didn't know what I was doing, if I was having sex and have [sic] a condom broke on me." Defendant admitted that he had ejaculated, that he put the condom in the toilet, and that they both got dressed.
 Kathy walked out of the trailer door first and got into the van. Defendant then drove Kathy home. After defendant stopped at her residence, Kathy asked for one more cigarette. Defendant testified that he could tell that Kathy was angry when she walked to her home. Defendant waited until Kathy was inside her home and then drove to Kimmie's Bar.
 Defendant had one beer at Kimmie's Bar. He tried to start his van to drive home, but it would not start. It took defendant about 15 to 20 minutes to walk home. Defendant went to sleep and awoke the next morning to a knock on the door by the police. Defendant was frightened by the nature of the complaint alleging that he had raped Kathy and by the demeanor of the police. Defendant denied that any sex act had occurred. Defendant basically denied everything because of the way he was approached by the police. He was under the assumption that the police would probably get more rude if he admitted that he had sex with Kathy.
 Detective Mark Junkins' Testimony
 Detective Mark Junkins went to defendant's trailer to investigate Kathy's complaint. Defendant told Detective Junkins that he had been with Kathy at the Corner Tavern the previous evening. They had traveled around and looked for some money to go to Club 57. After dropping Kathy's cousin off at the Corner Tavern, defendant and Kathy went to his trailer to look for money. Defendant gave Kathy a beer, and after not finding any money, he drove her home. Defendant denied that he had sexual intercourse with Kathy, ...